Hot-air furnace.



W. R. KNIGHTS.

HOT AIR PURNAGB.

APPLICATION FILED JAN.15,1908.

' UNITED' sTATEs PATENT OFFICE.

I-IOT-AIR FURNACE.

Specication of Letters Patent.

Patented Apr. 4, 1911.

Application led January 15, 1906. Serial No. 295,995.

To all 'whom it may concern.:

Be it known that I, WILLIAM R. KNrGH'rs, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and "State of Minnesota, have invented certain tai'ns to make and use the same.

My invention relates to hot air furnaces, and has for its object to improve the same Yin the several particulars hereinafter noted.

The invention consists of the novel devices and combinations of devices hereinafter described and defined .in the claim.

In the accompanying drawings, which Iillustrate my invention, like characters indi- Fi l.

f the parts of the furnace, it is only desirable for the purposes of this case to note the fire pot 1, the secondary combustion chamber or heat cylinders 2, and the exterior casing 3. The heat cylinders 2, it will be understood, are in communication with the main fire chamber and fire-pot, and with a draft flue or pipe (not shown), such being the standard construction. The hot air pipes 3b lead upward from thetop of the casing 3 in the usual way. The numeral 4 indicates cold air return pipes which open into the lower portion of the casing 3.

'My invention has' for its particular object, first, the precipitation and collection of all dust and dirt carried from the room, or several rooms, back into the hot air chamber of the furnace by the cold air return pipe or pipes, and second, to evaporate into the. air circulated through the a1r chamber of the furnace suflicient water to prevent dryness of the air, or in other words, to keep the air moist and in proper condition from a hygienic point of view.

To the above ends, I provide in connec? tion with the cold air return pipe, a Water containing pan or vessel in the form of a drawer, some portion of which is located directly under the lowermost or delivery end of such cold air return pipe, or is so related thereto that the air, is passing from the cold air return pipe to the hot air chamher of the furnace, will move in a downward direction toward the Water in said pan, and hence will precipitate dirt and dust carried by the air directly into the water. In this way,V the dust or dirt is removed from the air and held by the water, and furthermore, rapid evaporation of water into the air is insured.

The i device is preferably arranged as shown in the drawings, wherein the numeral `5 indicates elongated water pans that are adapted to be slid to and from working position through neck-like extensions 6 of the shell or casing 3. The cold air return pipes 4, Qf which, in the drawings, only two are shown, open directly into the upper portion of thecase extension 6 and, 1t will be noted, the said cold air pipes, just above their junction with the extension 6, are curved outward, so that the air is caused to make amore abrupt turn in passing from the cold air pipes into the air heating chambers of the furnace. It will also be noted that when the pans 6 are in working position, their outer end plates close the openings in the outer ends of the case extension 6. The case extension 6 and the pans 5 are made much wider than the cold air return pipes, and baille plates 7 are preferably hung from the upper plates of the case eX- tension 6, just inward ofthe cold air return pipes 4. These baille plates 7 preferably depend into the water e contained in the pans 5, and they are hinged at their upper edges so that the said pans may be readily removed from the furnace. Furthermore, by reference tov Fi s. 2 and 3, it will be noted that the baffle p ates 7 extend Very much less than completely across the pans 5, so that free passages are left for the air on the op posite sides thereof. The said baiiie plates, however, cause the returning cold air to move in a horizontal direction, as well as in a vertical direction, in passing from the cold air return pipesinto the hot air chambers of the furnace, thereby increasin the tendency to precipitate the dust into t e water contained in the pans 5. It is also important to lower portion of the fire box 1, so that the Water contained therein will be heated, and thereby greatly increase the rate of evaporation. By moving the inner extremities of the pans directly into contact with, or

slightly out of contact With, the fire box 1, the Water may be evaporated more rapidly, as may be required.

It Will be observed that the casing extensions 6 have a cross section very greatly in excess of that of the corresponding cold air return pipes. This is important because the velocity of the returning dust laden air is reduced in passing from the cold air return pipe through the said extension; and this, as is evident, gives very much better chance for theu dust to settle into the Water.

V The improved dust collecting and evapolittle.l if anything, to the cost of the furnace, and greatly improves the action thereof both by rendering hot air heating systems cleaner and the air moist -and in proper condition to be taken into the lungs. v

What I claim and desire to secure by LetloWs:

Inl a hot air furnace having an extension 6 and a cold air pipe 4 opening into the top of said extension, of a Water pan 5 seated Within the air chamber of said furnace and in the said extension 6, a portion thereof being below the delivery end of said' cold air pipe, and a deiecting plate 7 located Within said extension 6 and extending less than completely across said pan 5, substantially as described.

In testimony whereof I aflix my signature in presence of tWo Witnesses.

WILLIAM R. KNIGI-ITS. Witnesses: y

MALre Horn, F. D. MERCHANT.

- The device above described adds very ,ters Patent of the United. States, is as folv i 

